using System;
using System.Text;
using System.Security;
using System.Security.Cryptography;

class App
{
	static void Main(string[] argv)
	{
		int len = 128;
		if (argv.Length > 0)
		{
			len = int.Parse(argv[0]);
		}

		byte[] buff = new byte[len / 2];
		RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();
		rng.GetBytes(buff);
		
		StringBuilder sb = new StringBuilder(len);
		for (int i = 0; i < buff.Length; i++)
		{
			sb.Append(string.Format("{0:X2}", buff[i]));
		}

		Console.Write(sb);
	}
}
